C.B.
I have that same problem with the folks who used to live in my house. I don't think changing the number will really help. They use a reverse directory and look up the street address and get the phone number associated with that address. The one thing I have done is start actually taking the calls, advise that I do not know the person and then get their information. I then make it perfectly clear that they are to note their records that that individual does not live here, I do not know them and they are not to call my number again looking for that individual. That's worked pretty well - we are down to only a couple of calls a month now!